This weekend TNT has been broadcasting the "From the Earth to the Moon" series. They also had the movie "Contact" on last night (a movie I really like, even if the South Park creators hate it :P ). Because of this, I started to think about humanity's place in the universe and the possibility of other forms of life "out there." Ever since I was young, I've had a love for astronomy. I'd read books on comets, black holes, planets, stars, etc., all the time. The universe was a fascinating place, something that was so huge that it was hard to fathom, yet the pictures taken from powerful telescopes would always kept the enormity of space somewhat maneable and less threatening [1]. The more I gained an interest in astronomy, the more I became aware of the idea of extra-terrestrial life. Fortunately, I never got into the mindset of some of the X-File-ish mentality of ETs in that I didn't think there were a lot of UFOs watching our planet, or that the government was trying to cover up evidence that aliens exists. Given the size of the universe, it became obvious that there would be other sentient life somewhere out there, but given the light speed barrier it would be impossible for ETs to visit us [2].

Therefore, one of the only ways that really has any scientific merit to finding evidence of sentient life in the universe is to listen for signals coming from ETs. Sagan's fictional book is great at theorizing what would happen if humanity found such a signal. But it seems like humanity as a race may start to go quiet in terms of its own broadcasting presence. A recent article in New Scientist (the August 14th, 2004 edition) suggests that because more signals are being sent through cable wires and directed satellites, we'll eventually look "radio-dead" to our nearby neighbors. The article suggests that organizations like SETI may want to start looking for signals sent via high-powered lasers. Another option is the ability to actually see planets orbiting other stars. While we can't see earth-sized planets orbiting other stars, technology may be able to allow us to do so.

The reason I bring this issue up is because I think finding direct evidence that sentient life exists outside of Earth would be one of the greatest discoveries of the human race (along with XML, of course). Of course, this sentient life may make its presence known by coming to our planet to suck us dry of our resources ;), but at least we'd know we're not alone. Sometimes I think finding this evidence will always be beyond our grasp. Other times I think we'll get lucky and find a signal from a nearby neighbor. I mean, if the nearest "neighbor" is in another galaxy, the chance of finding out about it would be extremely small. But if it's close, we have a chance of discovering it. I just hope that humanity doesn't severely hinder its own existence so we don't end up being an interesting archelogical find when creatures from planet Xaxlov fly by our solar system and think, "wow, were these creatures really stupid! Look, they actually wasted millions of 'dollars' debating trivial political issues and fought wars over minor religious differences. Let's keep this planet in mind so we can teach our offspring not to follow in their footsteps."

[1] If you're interested in astronomy pictures, look no further than APOD. Every day you get a new picture, and they're usually very stunning.

[2] Of course, there may be something in physics that we don't understand yet that would allow us to safely travel at superlight speeds. Unfortunately, from what I understand we have no idea how to travel at such speeds, so for now faster-than-light travel is confined to the science-fiction books I read.